Population status

Townsend's Warbler
(Setophaga townsendi)

The Breeding Bird Survey provides the most reliable data for monitoring the population of Townsend’s Warbler in Canada, despite poor coverage at high elevations and in wet forest habitat. The results suggest an estimated 41% decrease in the national population since the early 1970s. Results at the regional level vary, suggesting little overall change in the Northern Pacific Rainforest Bird Conservation Region (BCR) population, while the Great Basin, Northern Rockies and Northern Interior Forest BCRs show moderate to large decreases. All BCRs with reasonably reliable results are displayed below. The Townsend's Warbler is below the lowest acceptable level relative to its national population goal (see Canada graph below).

 

Population goal and acceptable levels of variation

Species/groupGoalLower levelUpper level
Townsend's WarblerMean abundance (first 5 years of survey)Goal minus 25% Not applicable

Breeding Bird Survey (BBS) - Canadian analysis

Additional information on: Breeding Bird Survey (BBS) - Canadian analysis

Table 1: Population trends by geographic area
Geographic areaTime Period Table 1 - footnote 1 Annual trend Table 1 - footnote 2 Limits
LowerUpper
Canada Select to view graph of the geographic area: Canada 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-1.2-2-0.3
Canada Select to view graph of the geographic area: Canada 2006-2016; Breeding Bird Survey (BBS) - Canadian analysis2006-2016-1.2-3.30.5
Northern Pacific Rainforest Select to view graph of the geographic area: Northern Pacific Rainforest 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-0.1-1.10.9
Great Basin Select to view graph of the geographic area: Great Basin 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-3.1-4.2-2
Northern Rockies Select to view graph of the geographic area: Northern Rockies 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-2016-2.2-3.7-0.8
North America Select to view graph of the geographic area: North America 1970-2016; Breeding Bird Survey (BBS) - Canadian analysis1970-20160.1-0.60.7
 

References